// initEngine parses the engine specification according to the
// dataDirRE regexp and instantiates an engine of correct type.
func initEngine(spec string) (storage.Engine, error) {
// Error if regexp doesn't match.
matches := dataDirRE.FindStringSubmatch(spec)
if matches == nil || len(matches) != 3 {
return nil, util.Errorf("invalid engine specification %q", spec)
}
var engine storage.Engine
var err error
if matches[1] == "mem" {
size, err := strconv.ParseInt(matches[2], 10, 64)
if err != nil {
return nil, util.Errorf("unable to init in-memory storage %q", spec)
}
engine = storage.NewInMem(size)
} else {
var typ storage.DiskType
switch matches[2] {
case "hdd":
typ = storage.HDD
case "ssd":
typ = storage.SSD
default:
return nil, util.Errorf("unhandled disk type %q", matches[1])
}
engine, err = storage.NewRocksDB(typ, matches[2])
if err != nil {
return nil, util.Errorf("unable to init rocksdb with data dir %q", matches[2])
}
}
return engine, nil
}
// initEngine parses the store attributes as a colon-separated list
// and instantiates an engine based on the dir parameter. If dir parses
// to an integer, it's taken to mean an in-memory engine; otherwise,
// dir is treated as a path and a RocksDB engine is created.
func initEngine(attrsStr, path string) (storage.Engine, error) {
attrs := parseAttributes(attrsStr)
var engine storage.Engine
if size, err := strconv.ParseUint(path, 10, 64); err == nil {
if size == 0 {
return nil, util.Errorf("unable to initialize an in-memory store with capacity 0")
}
engine = storage.NewInMem(attrs, int64(size))
} else {
engine, err = storage.NewRocksDB(attrs, path)
if err != nil {
return nil, util.Errorf("unable to init rocksdb with data dir %q: %v", path, err)
}
}
return engine, nil
}